Rubber products are required to be manufactured without hazardous substances exceeding the limit values and without the use of banned hazardous substances that could endanger human health.

1. Heavy metals
The type and grade of raw materials for rubber products affect the content of heavy metals. Therefore, care should be taken to avoid or reduce the use of raw materials containing chromium and nickel (e.g. zinc-chromium yellow containing hexavalent chromium and antioxidant NBC containing nickel). Chromium plating of moulds and skeletons also brings chromium into the rubber, so new chromium plating technologies that replace hexavalent chromium with trivalent chromium have to be developed.
Since the EU ELV Directive and the EEE RoHS Directive have been implemented, the design of formulas and production processes for rubber products to achieve "lead-free" has become an important issue.
Adoption of lead-free vulcanisation system
② Eliminate the hose wrapped lead vulcanisation process
③Use of environmentally friendly adhesives
Some rubber/metal hot vulcanising adhesives (e.g. Chemrock 220, 250, 252) contain lead compounds in their components, which can cause products to exceed lead standards.

2. Bromine flame retardants
According to the relevant EU directives, polybrominated biphenyls (PBB) and polybrominated diphenyl ethers (PBDE) are banned/restricted. Although it is difficult to find an effective flame retardant to replace DecaBDE in the rubber and plastics industry, and the fire department has also raised objections, the European Commission adopted a resolution on 13th October 2005, deciding to exempt "DecaBDE in polymer applications".

3. Polycyclic Aromatic Hydrocarbons (PAHs)
At present, there are 16 kinds of PAHs restricted by EU and other countries, and the most important PAH is the well-known benzo(α)pyrene. In recent years, China's exports of electrical and electronic products have been repeatedly returned by European countries, some of which are related to the rubber and plastic products PAHs exceeding the standard.
① Carbon black
② Processing oil

4. Specific amines
The EU Directive 2002/61/EC and the eco-textile standard "Oeko-Tex-Standard 100" restrict the sale and use of hazardous substances such as azo dyes. The so-called "Specific Amines" are carcinogenic aromatic amines produced by the decomposition of azo dyes under specific (i.e. reducing) conditions, and there are 24 of them.

5. N-nitrosamines
Certain rubber auxiliaries with a secondary amine structure react with nitrosating agents (NOx) to form carcinogenic N-nitrosamines. The German regulation TRGS552 (effective January 1988) prohibits 12 types of carcinogenic N-nitrosamines, involving a variety of rubber auxiliaries that are widely used in China.